Viewing 32 posts - 1 through 32 (of 32 total)
  • Why do some rims just not seal?🤬🤬🤬🤬
  • Premier Icon silasgreenback
    Full Member

    More tubeless woes.

    My set up process is always the same. Clean rims with finest unleaded. Wipe with Autoglym detar stuff then leave to dry for a couple of hours. Final wipe with a clean cloth.

    Single wrap of tape starting from opposite the valve. Overlap up to 15 or 20cm. Valves – used all sorts but settling on Muc-off.

    A small X at the valve hole and push the valve through. Tighten lock ring hand tight whilst pushing down on the inner valve to gently squash the rubber.

    Some wheels just pop and stay up. No sealant required. Occasionally I get a nightmare that will not seal. Regardless. And it is without fail the valve that leaks. Its not the tape because a) wrapped up to the rim wall so tyre sits on it b) always 0 sealant underneath the tape. C) if i push the valve enough i can hear air. Regardless of how tight i do the valve lock ring.

    Tried umpteen sealants, all of the muc-off rubber valve grommets and even a small piece of inner tube between rim and valve.

    I used to do 2 wraps of tape but i could see wrinkles at the valve area as it was too thick. Switched from Tesa / stans tape to muc-off tape as its more flexible so doesnt wrinkle as much if the valve hole isnt perfect. Seems better but no home run.

    I have a front that seals perfectly and a rear that wont. 4th attempt, sore thumbs, shredded finger ends and WTF🤬🤬🤬🤦‍♂️🤦‍♂️

    Final thoughts are Gorilla tape as that sorted my fat 50mm rims with cutouts. But getting sick of it. And i have in my head gorilla tape weighs a ton compared to normal stuff!

    The rim in question came taped from the shop so just insert valve. Lost 20psi a day. What else can i do to get the valve to seal?

    Premier Icon scotroutes
    Full Member

    Don’t just cut an X at the valve. Remove all the excess tape so that there is a round hole. A modellers rat-tail file can help get a nice round, even hole in the tape.

    The sealant should deal any small holes though. I assume your problems exist even when sealant is in and you’ve shaken it around to make sure it’s been splashed over the valve hole a few times?

    Premier Icon silasgreenback
    Full Member

    Problems with sealant yes.

    Am i aiming to have no tape at all round the valve hole?

    Premier Icon temudgin
    Free Member

    Not tried this, but would a smear of neutral cure silicone around the valve rubber before tightening help?

    Premier Icon davros
    Free Member

    Melt the valve hole with a hot skewer.

    Premier Icon nickc
    Full Member

    I stopped cutting the valve hole, and just poke the valve through from the inside, yes it’s a bit more “untidy” than a nice neat cut, but I don’t get leeks around the valve any more.

    Premier Icon silasgreenback
    Full Member

    Tempted with the silicon approach!

    Guess i need to go try again and be a little more fastidious with the valve hole.

    Rewrap again or try and sort the existing tape hole?

    Premier Icon scotroutes
    Full Member

    Nothing to lose by trying to fix what you have.

    Premier Icon davros
    Free Member

    My mate really struggled with his hunt rims but i sorted it with an extra square of tape around the valve and melted rim hole. Also can depend on the shape of the rim bed and valve bung. Some combinations struggle.

    Premier Icon chriscubed
    Full Member

    Some valves come with different shaped rubber pieces, round and squarer profile ones for different shaped rims.

    Could be the rubber piece is not matched to the profile of your time?

    Premier Icon joebristol
    Full Member

    I’ve never had a problem with a valve or tape leaking air – maybe I’m lucky. Used DT Swiss rims / wtb rims so not the same make each time. I’ve used Stan’s, Hunt, Joe’s, DT Swiss and Rimpact valves. I’d say the Stan’s were my least favourite – DT Swiss have been the best ones.

    On the hole through the tape I normally just make a small hole with something sharp and pointy and push the valve through that. No ‘x’ etc.

    Tape wise I’ve used the yellow wtb tape (think the same as Stan’s, Joe’s and Tesa) and DT Swiss. DT Swiss is stickier / feels thicker / goes on smoother and looks nicer to me. I heat the rim with a hot hairdryer and heat the tape before stretching it on. I then warm it and make sure it’s smoothed down where it gets to the edge of the rim. Always go 2-3mm wiser tape than the quoted internal width of the rim.

    DT Swiss valves don’t have a round rubber bung where they meet the rim – they have a longer rectangle piece – obviously works well with DT Swiss rims but probably depends on the profile of your rim. I finger tight screw it up initially – but I do tend to give another couple of turns with a small out of multi tool pliers just to be sure. Not so much you over squeeze the rubber sealing o ring on the lock ring though.

    Stan’s standard sealant – never found any reason to use any other sealant Tbh.

    Premier Icon chrisdw
    Free Member

    As others have said. Melt the hole with a hot skewer or pick and push all the excess molten bits down so you have a completely flat surface. The x allows creasing and leakage I find. It can also tear further on the cuts.

    With the muc off valve. Stick a 4mm Allen key in the top to aid pushing down and compress the rubber. And tighten up the lock ring. The solid thicker cone rubber is the only one I use. It works with every rim I’ve tried so far. The others are a bit iffy.

    Premier Icon sixtoes
    Full Member

    If you replace the tape try an awl to make the hole rather than cutting a cross.

    Premier Icon bikerevivesheffield
    Full Member

    Poke hole with file and then file the edges to get the excess tape removed

    Premier Icon jamesoz
    Full Member

    Self adhesive tube patch over the valve hole, on the inside obvs.
    On some troublesome rims I cut a short length of tape and tape across the rim joint all the way across.

    Premier Icon thenorthwind
    Full Member

    Tighten lock ring hand tight whilst pushing down on the inner valve to gently squash the rubber.

    While it’s definitely possible to overtighten and get a worse seal in this sort of situation, I’ve had valves that I just can’t get tight enough by hand to seal, and needed pliers to fix. Feels like the wrong thing to do, and makes a mess of the lockring unless you protect it with a rag or something, but it’s saved me a few times. Understand the rage when it doesn’t work!

    Premier Icon FOG
    Full Member

    I’ve just had weird one with some spare wheels. I was putting them on for the summer but the rear wheel has somehow popped it’s bead and won’t seal. So, same tyre, same wheel, same tape, same valve, same sealant . They were hung up in the garage over the winter and were fine back in the autumn so why won’t one seal now? I have had the offending bead completely off and cleaned extra sealant but it won’t seal. Why?

    Premier Icon footflaps
    Full Member

    I just poke a hole with a braddle then force the valve through the tiny hole. Set some up with 10+ year old Stans rim tape the other day and worked fine once I’d ridden them a bit – rear did struggle to hold air till taken off road, which seemed to settle it down.

    Premier Icon plus-one
    Free Member

    Rimming is a fine art 😉

    Premier Icon kerley
    Free Member

    I’ve had valves that I just can’t get tight enough by hand to seal, and needed pliers to fix

    That is what I had to do own the rear wheel a few weeks back. Front was fine but rear was losing 20psi a day. Put in tub of water and could see a bubble coming out every few seconds so did up with pliers and stopped. Tyre and stayed up ever since.

    Premier Icon silasgreenback
    Full Member

    went back to the solid cone instead of the rectangle valve seal bit of tidying the hole and a new valve core.

    Holding a steady 38psi after a few bounces, wheel spins, a couple of quick rides round the block and left to settle all day in the garage. Fingers crossed they dont loose much over night then it’s drop to 20-25psi and away we go. This time 🤦‍♂️🤦‍♂️

    Premier Icon jonba
    Free Member

    The valve may be where the air is coming out but it may not be where the problem is. I had a similar problem on an old wheel. It was a crack else where. It was leaking there and coming out the valve hole.

    Premier Icon argee
    Full Member

    It’s the curse of tubeless tape, i’ve prepped a wheel perfectly before, IPA all round, cleaned, tape, heat gun, etc, etc, then try to cut a hole for the valve and it turns into a bloody tear, it would be funny if the tape wasn’t so expensive!

    As others say, melt the whole, and use something circular, i use a small circular file with a needle point, stopped using a knife after that last nightmare!

    Premier Icon el_boufador
    Full Member

    The valve may be where the air is coming out but it may not be where the problem is. I had a similar problem on an old wheel. It was a crack else where. It was leaking there and coming out the valve hole.

    I’ve had this in the past.

    If it’s a new setup I put a tube in first and leave overnight to make sure all the tape is well stuck down.

    Premier Icon tone46
    Free Member

    Had a real problem with one recently as well. Would hold air, seal great but then be flat in the morning. Tested it with soapy water in spray bottle… nothing, valve stem, rim, not a single bubble. Went riding, next morning flat! Interweb searching came across a thread and a guy said put a bit more sealant in and bounce it like a basket ball? Well, well, it only worked, Been holding air ever since. Go figure!

    Premier Icon Yak
    Full Member

    I single wrap with tesa/stans tape and overlap the valve hole. Push through a small philips to make a hole a bit smaller than the valve so the valve is a tight fit. Hand tighten the valve, tyre on, 2 cups of stans and inflate.
    Then slowly rotate the wheel both sides up to coat the inside, then bounce/throw/catch the wheel a lot with plenty of backspin. I like to send it across the patio then catch it on the return. Soft compound tyres take a real throw as they suck up the bounce.

    Premier Icon silasgreenback
    Full Member

    Definitely the valve hole in this case. 38psi yesterday after final fettle with it. 38psi this morning. Finally!!

    Premier Icon mattsccm
    Free Member

    I have the overlap of tape at the valve. Gives it a bit more to seal any holes I reckon. Just jab a hole with a screw driver. If in doubt another layer of tape helps. Keep adding!
    I have had a pair of identical rim with identical new tyres play up. One sealed and held air with no sealant at all. The other needed several goes and layer of tape, sealant etc.

    Premier Icon easily
    Free Member

    Note to self: never go tubeless.

    No offence intended people, it’s fascinating reading stuff like this.

    Premier Icon stevenmenmuir
    Free Member

    Set up my new Hope rear wheel this weekend. Taped it last night whilst watching the tennis. Biggest job was taking the old sealant of the bead of the tyre today. Made a hole for the valve with a pencil. Tyre half on, put some sealant in, rest of tyre on and tyre pumped up without the valve core in. Left it for a bit then put the core in and pumped up again. Spun it a few times to spread sealant. Relatively painless.

    Premier Icon scotroutes
    Full Member

    But you’re not seeing all threads every time someone easily installs a tubeless setup. It would all get a bit boring.

    Premier Icon avdave2
    Free Member

    After seeing it suggested on here I use a soldering iron to make the hole. I did 4 wheels yesterday and they all went up and stayed up without sealant.

    Tubeless can be a faff, a faff that all occurs in my nice warm dry garage with music or a podcast and as much tea as I can drink. Replacing and fixing tubes is a faff to be performed on a cold wet trail in a howling gale.

Viewing 32 posts - 1 through 32 (of 32 total)

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